This invention relates to a tufting machine, and more particularly to a cut pile looper apparatus to form cut pile tufts having substantially equal legs.
Traditionally, cut pile has been produced in tufting machines by a reciprocable looper or hook engaging and holding a loop of yarn carried through a base fabric by a reciprocable needle, and a reciprocable knife cooperating with one side of a looper to cut the loop of yarn into two separate yarn ends or legs. As the knife reciprocates along and against one side of the looper, the yarn loop is cut on one side of the hook to form two unequal cut pile ends or legs. Such cutting is referred to in the industry as a "J-cut", because the long leg of the yarn loop is J-shaped, or because the unequal strands of the yarn segments stitched into the base fabric are J-shaped. Many manufacturers of cut pile fabrics, particularly carpets, have found the conventional "J-cut" pile to be objectionable because of the unequal height or length of the pairs of ends or legs in each cut loop, which presents an uneven pile surface.
Various means have been utilized in an attempt to eliminate the uneven and unattractive cut pile surface created by the formation of the "J-cuts". One example of such an effort is to shear the cut pile fabric with a shearing machine after the tufting operation in order to make the cut pile legs even. Usually, this procedure requires several passes of the carpet over the shearing machine.
Another method to neutralize the effect of the "J-cuts" is to alternately laterally shift the needle bar continually to create zig-zag rows of stitching which obliterate the "corduroy effect" of straight rows of "J-cuts" stitching.
Other attempts to eliminate the "J-tufts" are disclosed in the following U.S. Pat. Nos.
______________________________________ 3,662,697 Passons et al May 16, 1972 3,730,115 Passons et al May 1, 1973 3,735,715 Passons et al May 29, 1973 3,880,101 Passons Apr. 29, 1975 British Patent Moss May 23, 1951 722,095 British Patent American Safety Razor May 24, 1955 782,079 Corporation British Patent Preston Engineers Apr. 22, 1966 1,143,342 (Precision) Limited ______________________________________
However, none of the above patents disclose a looper apparatus incorporating cut pile hooks in which the bill of the hook is bent or formed to provide a free end or pointed end portion which is transversely offset from the portion of the bill which cooperates with a knife to cut the loop.